The present invention concerns a method for the crosslinking of cathodically depositable, if necessary pigment, dyestuff, filler, solvent, varnish adjuvant and additional crosslinking components-containing coating agents, based upon a water-soluble or -dispersible, at least partially present as salt, nitrogen based cationic resin. It concerns likewise the hardened coating, which is obtained by the crosslinking process according to the present invention.
The known and practiced polyisocyanate-crosslinking of cathodically depositable coating agents is so far still not optimal, as the temperature necessary herewith is relatively high and amounts to about 180.degree. C. Through the cleavage of alcohol used for blocking of the diisocyanate, there arises in particular considerable baking loss, which brings about relatively great emissions. Also less than optimal is the maximum obtainable adhesive strength of the coating on steel, a characteristic which is still desired, completely irrespective of any requirements for the use of adhesives based upon heavy metal compounds, in particular lead compounds.